Bug 1629979 – CVE-2018-16745 mgetty: Stack-based buffer overflow in fax_notify_mail() in faxrec.c

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Bug 1629979 - (CVE-2018-16745) CVE-2018-16745 mgetty: Stack-based buffer overflow in fax_notify_mail() in faxrec.c

Summary:	CVE-2018-16745 mgetty: Stack-based buffer overflow in fax_notify_mail() in fa...

Status:	NEW

Aliases:	CVE-2018-16745

Product:	Security Response
Classification:	Other
Component:	vulnerability (Show other bugs)
Sub Component:
Version:	unspecified
Hardware:	All Linux

Priority	low Severity low
Target Milestone:	---
Target Release:	---
Assigned To:	Red Hat Product Security
QA Contact:
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URL:
Whiteboard:	impact=low,public=20180913,reported=2...
Keywords:	Security

Depends On:	1629980 1631243
Blocks:	1629987
	Show dependency tree / graph

Reported:	2018-09-17 13:43 EDT by Pedro Sampaio
Modified:	2018-09-20 19:40 EDT (History)
CC List:	8 users (show)

See Also:
Fixed In Version:	mgetty 1.2.1
Doc Type:	If docs needed, set a value
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RHEL 7.3 requirements from Atomic Host:
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Attachments	(Terms of Use)
upstream patch (501 bytes, patch) 2018-09-20 05:40 EDT, Riccardo Schirone	no flags	Details \| Diff
Add an attachment (proposed patch, testcase, etc.)

Groups: None (edit)

Description Pedro Sampaio 2018-09-17 13:43:51 EDT

An issue was discovered in mgetty before 1.2.1. In fax_notify_mail() in faxrec.c, the mail_to parameter is not sanitized. It could allow a buffer overflow if long untrusted input can reach it.

References:

https://www.x41-dsec.de/lab/advisories/x41-2018-007-mgetty

Comment 1 Pedro Sampaio 2018-09-17 13:44:30 EDT

Created mgetty tracking bugs for this issue:

Affects: fedora-all [bug 1629980]

Comment 3 Riccardo Schirone 2018-09-20 05:37:54 EDT

Mitigation:

Make sure the `notify` option in /etc/mgetty+sendfax/mgetty.config does not contain more than 150 characters and that the file is readable and writable only by root.

Comment 4 Riccardo Schirone 2018-09-20 05:38:53 EDT

Only root can write to /etc/mgetty+sendfax/mgetty.config and set the `notify` option which `mail_to` is set to when the program runs. Thus, this flaw is very unlikely to be exploited since it would require root to set a very long `notify` value.

Comment 5 Riccardo Schirone 2018-09-20 05:40 EDT

Created attachment 1485086 [details]
upstream patch

This patch was extracted from mgetty-1.2.1.
It is the same patch as the one for CVE-2018-16744.

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